Dual zone temperature control of upper electrodes

ABSTRACT

A system and method of plasma processing includes a plasma chamber including a substrate support and an upper electrode opposite the substrate support, the upper electrode having a plurality of concentric temperature control zones and a controller coupled to the plasma chamber.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority from U.S. Provisional PatentApplication No. 61/563,509 filed on Nov. 23, 2011 and entitled “DualZone Temperature Control of Upper Electrodes,” which is incorporatedherein by reference in its entirety for all purposes. This applicationis related to U.S. patent application Ser. No. 13/301,725, filed Nov.21, 2011, entitled “Triode Reactor Design With Multiple RadiofrequencyPowers,” and to U.S. Provisional Patent Application No. 61/563,021,filed Nov. 22, 2011, entitled “Systems And Methods For Controlling APlasma Edge Region,” the disclosures of which are incorporated herein intheir entirety by reference for all purposes. This application isrelated to U.S. Provisional Patent Application No. 61/563,510, filedNov. 23, 2011, entitled “Multi Zone Gas Injection Upper ElectrodeSystem” which is incorporated by reference herein in its entirety andfor all purposes.

BACKGROUND

The present invention relates generally to plasma processing methods andsystems and more particularly, to methods and systems for having dualtemperature zones on an upper electrode in a plasma chamber.

FIG. 1A is side view a typical plasma chamber 100. The typical plasmachamber 100 has a single showerhead type upper electrode 102, asubstrate support 140 for supporting a substrate 130 as the substrate isbeing processed by a plasma 150.

FIG. 1B is a more detailed view of a typical upper electrode in theplasma chamber 100. Typically, the showerhead type upper electrode 102includes several layers 104, 110, 120, 125. A surface layer 104 includesan exposed plasma surface 104A and multiple outlet ports 106. Theexposed plasma surface 104A is the surface of the surface layer that isexposed to the plasma 150. The outlet ports are substantially evenlydistributed across the plasma chamber 100 so as to maintain a uniformdistribution of the process gases.

Behind the surface layer 104, is a gas distribution layer 110. The gasdistribution layer 110 includes multiple gas passages 112, 114 todistribute the process gases evenly to the ports 106 across the surfacelayer 104. The multiple gas passages 112, 114 are coupled to one or moreexternal process gas sources, not shown. A great amount of effort isplaced in detail in the design of the multiple gas passages 112, 114 soto ensure that the multiple gas passages evenly distribute the processgases to each of the outlet ports 106 and therefore evenly throughoutthe plasma chamber 100.

Behind the gas distribution layer 110 is a temperature control layer120. The temperature control layer 120 includes elements 122. Elements122 can heat or cool the temperature control layer 120, as desired, tocontrol the temperature of the upper electrode 102. The temperature ofthe upper electrode 102 is controlled as one aspect of controlling theplasma processing occurring in the plasma chamber 100. A great amount ofeffort is placed in the detailed design of the temperature control layer120 so as to maintain a uniform temperature across the surface layer104.

Unfortunately, for various reasons, the plasma processing is not alwaysuniform across the center to edge of the substrate 130. In view of theforegoing, what is needed is a system and method of manipulating theplasma processing from the center to the edge along of the substrate130.

SUMMARY

Broadly speaking, the present invention fills these needs by providing asystem and method of manipulating the plasma processing along the centerto edge of the substrate. It should be appreciated that the presentinvention can be implemented in numerous ways, including as a process,an apparatus, a system, computer readable media, or a device. Severalinventive embodiments of the present invention are described below.

One embodiment provides a system for plasma processing including aplasma chamber including a substrate support and an upper electrodeopposite the substrate support, the upper electrode having multiple,concentric temperature control zones and a controller coupled to theplasma chamber.

The substrate support can include an edge ring proximate to an outerperimeter of a supported substrate. The edge ring can include atemperature control mechanism capable of heating or cooling the edgering to a selected edge ring temperature. At least one of the concentrictemperature control zones extends outside a radius of the edge ring.

Each one of the concentric temperature control zones can include atemperature control mechanism. The temperature control mechanism iscapable of heating or cooling a respective one of the concentrictemperature control zones to a corresponding selected temperaturecontrol zone temperature.

The substrate support can be capable of heating or cooling a supportedsubstrate to a selected substrate temperature. The plasma chamber canalso include a plasma confinement structure. The plasma confinementstructure extends outside a radius of the substrate support.

The plasma processing system can also include an RF source coupled tothe inner upper electrode. The RF source coupled to the inner upperelectrode can be capable of heating the inner upper electrode.

Another embodiment provides a plasma processing system including aplasma chamber and a controller coupled the plasma chamber. The plasmachamber including a substrate support including an edge ring proximateto an outer perimeter of a supported substrate. The edge ring includes atemperature control mechanism capable of heating or cooling the edgering to a selected edge ring temperature. An upper electrode is oppositethe substrate support. The upper electrode includes multiple, concentrictemperature control zones. At least one of the concentric temperaturecontrol zones extends outside a radius of the edge ring. A plasmaconfinement structure is also included in the plasma chamber. The plasmaconfinement structure extends outside a radius of the substrate support.

Yet another embodiment provides a method of selecting an edge etch rateusing a dual temperature zone upper electrode. The method includescreating a plasma in a plasma chamber, reducing an edge etch rateincluding increasing an inner upper electrode temperature to atemperature greater than an outer upper electrode temperature andincreasing an edge etch rate including decreasing an inner upperelectrode temperature to a temperature less than an outer upperelectrode temperature.

The outer upper electrode temperature can be in a plasma confinementstructure. The plasma confinement structure extends outside a radius ofa substrate support in the plasma chamber.

The inner upper electrode temperature can be opposite a substratesupport in the plasma chamber. Reducing the edge etch rate can furtherinclude increasing a substrate temperature to a temperature greater thanan outer upper electrode temperature. Increasing an edge etch rate canfurther include decreasing an inner upper electrode temperature to atemperature less than an edge ring temperature, the edge ring proximateto an outer perimeter of a substrate support in the plasma chamber.

Increasing the inner upper electrode temperature can include applying anRF signal to the inner upper electrode. Applying the RF signal to theinner upper electrode can include cooling the inner upper electrode.

Heating the inner upper electrode can include maintaining the innerupper electrode at a set point temperature including applying the RFsignal to the inner upper electrode during a first period andsimultaneously cooling the inner upper electrode during the first periodand stopping applying the RF signal to the inner upper electrode duringa second period and simultaneously heating the inner upper electrodeduring the second period.

Heating the inner upper electrode can include maintaining the innerupper electrode at a set point temperature including applying the RFsignal to the inner upper electrode during a first period andsimultaneously heating the outer upper electrode during the first periodand stopping applying the RF signal to the inner upper electrode duringa second period and simultaneously cooling the outer upper electrodeduring the second period.

Other aspects and advantages of the invention will become apparent fromthe following detailed description, taken in conjunction with theaccompanying drawings, illustrating by way of example the principles ofthe invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be readily understood by the followingdetailed description in conjunction with the accompanying drawings.

FIG. 1A is side view a typical plasma chamber.

FIG. 1B is a more detailed view of a typical upper electrode in theplasma chamber.

FIG. 2 is a plasma chamber, in accordance with embodiments of thepresent invention.

FIG. 3A is a schematic diagram of the edge region of the plasma chamberin accordance with embodiments of the present invention.

FIG. 3B is a graph of the density of the ions and neutrals, inaccordance with embodiments of the present invention.

FIG. 3C is a graph of the relative etch rates across the radius of thesubstrate, in accordance with embodiments of the present invention.

FIG. 3D is a schematic diagram of a portion of the plasma chamber top,in accordance with embodiments of the present invention.

FIG. 4A is a flowchart diagram that illustrates the method operationsperformed in selecting an edge etch rate using a dual temperature zoneupper electrode, in accordance with embodiments of the presentinvention.

FIG. 4B is a flowchart diagram that illustrates the method operationsperformed in maintaining a set point temperature of the upper electrode,in accordance with embodiments of the present invention.

FIGS. 5A and 5B are schematic diagrams of multi zone gas injection upperelectrode, in accordance with embodiments of the present invention.

FIG. 5C is a graph of the effectiveness of tuning gas injections in eachof the gas injection zones, in accordance with embodiments of thepresent invention.

FIGS. 5D and 5E are graphs of the relative densities of the tuning gasand the process gas, in accordance with an embodiment of the presentinvention.

FIG. 6 is a cross-sectional view of a plasma chamber having the multizone gas injection upper electrode, in accordance with embodiments ofthe present invention.

FIG. 7A is a schematic diagram of a distributed gas supply feed, inaccordance with embodiments of the present invention.

FIGS. 7B-F are schematic diagrams of plasma arrestors, in accordancewith embodiments of the present invention.

FIG. 8 is a flowchart diagram that illustrates the method operationsperformed in selecting an edge etch rate using distributed gas zones, inaccordance with embodiments of the present invention.

FIG. 9 is a simplified schematic diagram of a computer system inaccordance with embodiments of the present invention.

FIG. 10A is a schematic diagram of the heated edge ring, in accordancewith embodiments of the present invention.

FIGS. 10B and 10C are schematic diagrams of a cam lock, in accordancewith embodiments of the present invention.

FIGS. 10D and 10E are schematic diagrams of electrical connections tothe heaters, in accordance with embodiments of the present invention.

FIG. 10F is a schematic diagram of an optical temperature sensor, inaccordance with embodiments of the present invention.

DETAILED DESCRIPTION

Several exemplary embodiments for system and method of manipulating theplasma processing along the center to edge of the substrate will now bedescribed. It will be apparent to those skilled in the art that thepresent invention may be practiced without some or all of the specificdetails set forth herein.

One approach to manipulating the plasma processing along the center toedge of the substrate 130 is to vary the temperature of the upperelectrode from the center 130A to edge 130B of the substrate. Anotherapproach to manipulating the plasma processing from the center to edgeof the substrate 130 is to manipulate the process gas concentrationsalong the center 130A to edge 130B of the substrate.

FIG. 2 is a plasma chamber 200, in accordance with embodiments of thepresent invention. The chamber of FIG. 2 includes RF power sources 220,222, and 224 with RF frequencies f₁, f₂, f₃, respectively, which areconnected to the bottom electrode 108 via the corresponding matchingnetworks. The upper electrode 201 is connected to a fourth RF powersource 242, having an RF frequency f₄, via switch 244 and matchingnetwork 246.

Further, the chamber includes a switch 244 that connects the upperelectrode 201 to either ground potential or to RF power source 242 viamatching network 246. A first heater 218 is situated above the upperelectrode 201, and a second heater 216 is situated above groundelectrode 248. The heaters are isolated from the upper electrode 201 andthe ground electrode by a layer of aluminum nitride material, althoughother insulators may also be utilized. Heater 216 controls thetemperature in the outer area of the ground electrode, and heater 218controls the temperature of the upper electrode 201. Each heater isoperable to be turned on or turned off independently during a substrateprocessing operation.

Controlling the temperature of the upper electrode may be utilized toadjust the response of the chamber. However, controlling the temperaturehas the limitation that the temperature cannot be changed quickly.Therefore, temperature control provides a slow response to changes inthe chamber. It is difficult to control each substrate-processingoperation utilizing temperature control of the upper electrode 201. Inaddition, there is an upper limit to the temperature that can be appliedto the silicon surfaces in the chamber 200.

The wafer processing apparatus further includes system controller 202,upper electrode power controller 206, heater controller 208, and powercontrollers 210, 212, and 214 for f₁, f₂, and f₃, respectively. Systemcontroller 202 receives a plasma recipe 204, which includes instructionsfor the different operations performed on the chamber. Processing of thewafer may be done in multiple operations, and each operation may requiredifferent settings in the chamber. For example, in one operation allfour RF power sources are turned on, while in other operations only 3,or 2, or 1 RF power sources are turned on, etc.

Based on the recipe 204, the system controller sets the operationalparameters of the chamber, including which RF power sources are turnedon or turned off, their voltages and power settings, the setting ofswitch 244, the settings for heaters degrees 216 and 218, the gassesused in the chamber, the pressure on the chamber, the duration of thewafer-processing operation, etc. In one embodiment, the systemcontroller 202 sends instructions to upper electrode power controller206 for the configuration of the power on the top electrode, whichincludes setting switch 244 to connect the top electrode to ground or toRF power, and turning on or off RF power 242, as well as setting thepower level for RF power 242.

System controller 202 interfaces with heater controller 208 to regulatethe temperature of the upper electrode 201. Heater controller 208regulates heaters 216 and 218 to control the temperature of the upperelectrode 201. A temperature sensor (not shown) provides information toheater controller 208 on the temperature of the upper electrode 201 inone or more points of the upper electrode. Therefore, heater controller208 may regulate the temperature on the upper electrode 201 by turningon or off the heaters to achieve a desired temperature during waferprocessing.

System controller also 202 interfaces with power controllers 210, 212,and 214, which regulate whether the corresponding RF power 210, 222, or224, is turned on or off, and if the power is turned on, to what powersetting. In one embodiment, the frequency of RF power source 242 is 400kHz. In another embodiment, the frequency is in the range from 400 kHzto 2 MHz, while in yet another embodiment the frequency is in the rangefrom 100 kHz to 10 MHz. In some operations, the three bottom RF powersare not turned on simultaneously, which allows having a higher frequencyat the top RF. In one embodiment, f₄ is different from the frequenciesat the bottom f₁-f₃ in order to avoid resonance on the chamber.

In one embodiment, the pressure in the chamber has a value between 20mTorr and 60 mTorr. In another embodiment, the voltage of the top powersource can be in the range of hundreds of volts (e.g., 100 V to 2000 Vor more), and the bottom RF power sources can have a voltage up to 6000V or more. In one embodiment, the voltage is 1000 V. In anotherembodiment, the voltage of the top RF power source has a value between100 V and 600 V, and the voltage of the bottom RF power sources has avalue between 1000 V and 6000 V. The pressure in the top chamber and thebottom chamber can have a value between 10 mTorr and 500 mTorr. In oneembodiment, the chamber operates at a pressure of 15 mTorr.

It is noted that the embodiment illustrated in FIG. 2 is exemplary.Other embodiments may utilize different types of chambers, differentfrequencies, other types of adjustments for the chamber configurationbased on the recipe, different pressures in the chamber, etc. Forexample, in one embodiment, the chamber is a CCP plasma chamber.Furthermore, some of the modules described above in the semiconductorwafer processing apparatus may be combined into a single module, or thefunctionality of a single module may be performed by a plurality ofmodules. For example, in one embodiment, power controllers 210, 212, and214 are integrated within system controller 202, although otherconfigurations are also possible. The embodiment illustrated in FIG. 2should therefore not be interpreted to be exclusive or limiting, butrather exemplary or illustrative.

Dual Temperature Zone Upper Electrode

FIG. 3A is a schematic diagram of the edge region of the plasma 200chamber in accordance with embodiments of the present invention. Theupper electrode 201 is thermally coupled to an inner heater 218 overregions 312A over the substrate edge region 130B. A plasma confinementstructure 252 extends outward beyond the substrate edge region 130B. Theconfinement structure 252 includes multiple confinement rings 254.

The substrate support 140 includes an edge ring 205. The edge ring 205includes an edge ring temperature control mechanism capable of heatingor cooling the edge ring to a desired edge ring temperature. The edgering 205 is adjacent to and outside the substrate edge region 130B. Theedge ring 205 is electrically isolated from the plasma by an edge ring307.

The confinement structure 252 also includes a protrusion 310 thatprotrudes downward from the upper portion of the plasma chamber. Theprotrusion 310 is thermally coupled to an outer heater 216.

An insulator 250 electrically and thermally insulates the upperelectrode 201 from the protrusion 310 and the inner heater 218 from theouter heater 216. The inner heater 218 can heat the upper electrode 201to a first desired temperature T1 (i.e., an inner electrodetemperature). The outer heater 216 can heat the protrusion 310 to asecond desired temperature T2 (i.e., an outer electrode temperature).Similarly, the edge ring 205 can be heated to a third desiredtemperature T3 (i.e., an edge ring temperature). The substrate 130 canbe heated to a fourth desired temperature T4 (i.e., a substratetemperature).

Densities of neutral molecules 302 and ions 304 in inner region 312A andouter region 312B can be selected by the relative temperatures T1, T2,T3 and T4. The neutral molecules 302 tend to buffer the reactivitybetween the etched surface and the ions 304. The neutral molecules 302tend to diffuse in the thermal gradient and attach to the coldestsurface of the relative temperatures T1, T2, T3 and T4. The relativedensities of neutral molecules 302 and ions 304 can manipulated be toselect etch rate.

By way of example, if T1>T2, then the relative density of the neutralmolecules 302 can be increased in the inner plasma region 312A over theedge 130B of the substrate 130 as compared to outer plasma region 312B.Thus decreasing the reactivity of the ions 304 over the edge 130B of thesubstrate 130. This decreased reactivity of the ions 304 results in acorrespondingly reduced etch rate of the edge region 130B of thesubstrate 130.

Similarly, if T2>T1, then the relative density of the neutral molecules302 can be decreased in the inner plasma region 312A over the edge 130Bof the substrate 130 as compared to outer plasma region 312B. Thusincreasing the reactivity of the ions 304 over the edge 130B of thesubstrate 130. This increased reactivity of the ions 304 results in acorrespondingly increased etch rate of the edge region 130B of thesubstrate 130.

By thus selecting the relative temperatures in the respective plasmaregions 312A, 312B, the corresponding etch rate can be increased ordecreased at the edge region 130B of the substrate 130.

FIG. 3B is a graph 350 of the density of the ions 304 and neutrals 302,in accordance with embodiments of the present invention. The graph 350has the radius of the substrate on the horizontal axis and the relativedensity of the ions 304 and neutrals 302 is shown on the vertical axis.

FIG. 3C is a graph 370 of the relative etch rates across the radius ofthe substrate 130, in accordance with embodiments of the presentinvention. The graph 370 has the radius of the substrate on thehorizontal axis and the etch rate is shown on the vertical axis ofmultiple etch iterations.

In the center region 130A of the substrate 130, the relative densitiesof the ions 304 and neutrals 302 are proximately equal and thecorresponding etch rate is approximately equal in that same portion ofthe substrate.

Toward the edge region 130B of the substrate 130, the relative densitiestend to vary at a drop-off line 352. Manipulating the relativetemperatures T1, T2, T3, as described above, can move the drop-off line352 left or right on the graph. Ideally, manipulating the relativetemperatures T1, T2, T3, as described above, can move the drop-off line352 to the right beyond the edge 130B of the substrate 130.

FIG. 3D is a schematic diagram of a portion of the plasma chamber top,in accordance with embodiments of the present invention. The innerheater 218, outer heater 216, ground electrode 248, gas distributionplate 610 and in insulator plate 382 (i.e., aluminum nitride or othersuitable insulator). The gas distribution plate 610 can have an RFsignal applied and thus typical thermo couples need filter networks tofunction effectively. Thus an optical temperature sensor 384 can be usedto monitor the temperature of the gas distribution plate 610.

It should be understood that the optical temperature sensor 384 can beplaced in any orientation and location that provides a suitable opticalview of the gas distribution plate 610. The optical temperature sensor384 can monitor the temperature of the gas distribution plate throughthe insulator plate 382. The ground electrode 248 can also include aplate heater.

The inner heater 218, the outer heater 216, the heated edge ring 205 andthe heating and cooling systems within the electrostatic chuck 140 canbe used individually and in combination to reduce the thermal ramp uptime in the plasma chamber. The inner heater 218, the outer heater 216,the heated edge ring 205 and the heating and cooling systems within theelectrostatic chuck 140 can also be used individually and in combinationto minimize and even substantially eliminate interim, partial coolingthat typically occurs during plasma processing in various portions ofthe plasma chamber. Reducing or eliminating interim, partial coolingimproves the processing speed and maintains the plasma chamber at a moreconstant temperature over time and over the desired surfaces in theplasma chamber. Reducing or eliminating interim, partial coolingimproves the consistency of the chemical processes as hot and cool spotsand intervals can effect the partial pressures of the various gases andplasma by products present in the chamber.

FIG. 4A is a flowchart diagram that illustrates the method operations400 performed in selecting an edge etch rate using a dual temperaturezone upper electrode, in accordance with one embodiment of the presentinvention. The operations illustrated herein are by way of example, asit should be understood that some operations may have sub-operations andin other instances, certain operations described herein may not beincluded in the illustrated operations. With this in mind, the methodand operations 400 will now be described.

In operation 405 a plasma 260 is created in the plasma chamber 262. Inan operation 410 an inquiry is made to determine whether to reduce theetch rate over the edge region 130B. If the edge region 130B etch rateis to be reduced then the method operations continue in an operation415. If the edge region 130B etch rate is not to be reduced then themethod operations continue in an operation 420.

In operation 415 temperature T1 and/or T4 is adjusted to be greater thantemperature T2 and T3, and the method operations continue in anoperation 430.

In operation 420, an inquiry is made to determine whether to increasethe etch rate over the edge region 130B. If the edge region 130B etchrate is to be increased then the method operations continue in operation425. If the edge region 130B etch rate is not to be increased then themethod operations continues in operation 430.

In operation 420 temperature T2 and/or T3 is adjusted to be greater thantemperature T1 and T4, and the method operations continue in operation430.

In operation 430, an inquiry is made to determine whether to the etchprocessing is complete. If the etch processing is complete then themethod operations can end. If the etch processing is not complete thenthe method operations continue in operation 410 as described above.

Another aspect of having a dual zone temperature control of the upperelectrode 201 is when the upper electrode has RF applied then heat willbe generated in the upper electrode and then cool when the RF is notapplied. The heaters 218, 216 provide dual zone temperature control theupper electrode 201 allows the central portion of the upper electrode201 to be cooled when the RF is applied and heated the RF is not appliedso as to maintain a desired set point temperature.

Another aspect of this invention is that the dual zone temperaturecontrol upper electrode can have the nonconductive surface 201A of theupper electrode 201 removable from the remainder of the electrode 201for servicing (e.g., cleaning).

FIG. 4B is a flowchart diagram that illustrates the method operations450 performed in maintaining a set point temperature of the upperelectrode 201, in accordance with one embodiment of the presentinvention. The operations illustrated herein are by way of example, asit should be understood that some operations may have sub-operations andin other instances, certain operations described herein may not beincluded in the illustrated operations. With this in mind, the methodand operations 450 will now be described.

In operation 452, a plasma 260 is created in the plasma chamber 262. Inan operation 454 an inquiry is made to determine whether RF is appliedto the upper electrode 201. If RF is applied to the upper electrode 201,then the method operations continue in an operation 456. If RF is notapplied to the upper electrode 201, then the method operations continuein an operation 458.

In operation 456, temperature T1 is reduced to maintain a set pointtemperature and the method operations continue in an operation 460. Inoperation 458, temperature T1 is increased to maintain a set pointtemperature and the method operations continue in operation 460.

In operation 460, an inquiry is made to determine whether to the etchprocessing is complete. If the etch processing is complete then themethod operations can end. If the etch processing is not complete thenthe method operations continue in operation 454 as described above.

Multi Zone Gas Injection Upper Electrode

Another approach to manipulate the etch rate from the center 130A toedge 130B of the substrate 130 is to adjust the process gasconcentrations radially from the center to edge of the substrate. Themulti zone gas injection from the upper electrode 501 allows a tuninggas (e.g., oxygen or other tuning gas) to be injected in different zonesradially outward from the center of the substrate 130. The tuning gaschanges the carbon/fluorine ratio at the surface of the substrate 130and thus changes the ion density and the corresponding etch rate.

The exemplary embodiment described herein includes three gas injectionszones in the upper electrode 501 however it should be understood thatmore than three zones could also be used (e.g., four or more zones).

FIGS. 5A and 5B are schematic diagrams 500, 550 of multi zone gasinjection upper electrode 501, in accordance with embodiments of thepresent invention. The multi zone gas injection upper electrode 501includes three gas injection zones 502, 504 and 506. A gas injectionzones 502, 504 and 506 are concentric.

The central gas injection zone 1, 502 has a central gas supply feed 552.Each of the concentric gas injection zones 504, 506 has respective gassupply feeds that are substantially evenly distributed around therespective circumference. By way of example, gas injection zone 2 504has four gas supply feeds 554 which are in turn supplied by a centraland spoke distribution manifold. Similarly, gas injection zone 3 506 haseight gas supply feeds 556 which are in turn supplied by a central andspoke distribution manifold.

The evenly distributed gas supply feeds 554, 556 can be aligned in theirrespective gas injection zone 504, 506. Alternatively, the evenlydistributed gas supply feeds 554, 556 can be offset (i.e., clocked) intheir respective gas injections zone 504, 506. The number of distributedgas supply feeds 554, 556 can be the same in each zone 504, 506 ordifferent numbers in each zone.

Each of the gas injection zones 502, 504, 506 can include one or moreconcentric gas plenum rings 562, 564, 566. The gas plenum rings 562,564, 566 are coupled in together by multiple gas channels 572, 574, 576within their respective gas injection zones 502, 504, 506. Each of thegas injection zones 502, 504, 506 include multiple outlet ports 532,534, 536 through the surface of the upper electrode and into the plasmazone.

FIG. 5C is a graph 520 of the effectiveness of tuning gas injections ineach of the gas injection zones 502, 504, 506, in accordance withembodiments of the present invention. Graph 521 is the effectiveness ofthe tuning gas injected in the gas injections zone1 502. Graph 522 isthe effectiveness of the tuning gas injected in the gas injections zone2504. Graph 523 is the effectiveness of the tuning gas injected in thegas injections zone3 506.

Referring to graph 521, the tuning gas injected in gas injection zone 1,502 is more consistently effective (i.e., more linearly predictable)across gas injection zone 1 than in gas injection zone 2, 504 and zone 3506. Referring to graph 522, the tuning gas injected in gas injectionzone 2, 504 is more consistently effective across gas injection zone 2than in gas injection zone 1, 502 or zone 3 506. Referring to graph 523,the tuning gas injected in gas injection zone 3, 506 is moreconsistently effective across gas injection zone 3 than in gas injectionzone 1, 502 or zone 2 504.

FIGS. 5D and 5E are graphs 580, 590 of the relative densities of thetuning gas and the process gas, in accordance with an embodiment of thepresent invention. Increasing the tuning gas (oxygen) flow rateincreases the presence of oxygen radicals proportionally to the flowrate. While the process gas (Fluorine) density is substantiallyconstant. Increasing the process gas (C4F8) flow rate decreases therelative density of the oxygen radical. The process gas radical(Fluorine) increases substantially proportionally to the process gasflow rate. The relative density of the oxygen radical controls thedegree of polymer removal without changing the plasma properties. Therelative density of the process gas impacts the effectiveness at lowerresidence times.

FIG. 6 is a cross-sectional view of a plasma chamber 600 having themulti zone gas injection upper electrode 501, in accordance withembodiments of the present invention. The cross-sectional view of aplasma chamber 600 illustrates the multi layer assembly forming the topportion of the plasma chamber. The multi zone gas injection upperelectrode 501 includes an inner electrode 201 and an outer electrode310. Insulator 250 separates the inner electrode 201 and the outerelectrode 310. Insulator 250 can be quartz or some other suitableinsulating material. The inner electrode 201 and the outer electrode 310can have different signals applied. By way of example an RF signal canbe applied to the inner electrode 201 and a ground or other DC potentialcan be applied to the outer electrode 310.

The inner electrode 201 is removably mounted on a gas distribution plate610. The gas distribution plate 610 distributes the process gases andtuning gases across the upper electrode 501. The gas distribution plate610 includes distribution plenums 562, 564, 566 and channels 572, 574,576 for evenly distributing the process gases and tuning gases.

The gas distribution plate 610 is mounted on an insulator plate 612. Theinsulator plate 612 electrically isolates the inner electrode 201 fromthe other layers forming the top portion of the plasma chamber 600. Thegas feeds 552, 554, 556 can include plasma arrestors 620. The plasmaarrestors 620 prevent plasma from lighting in the gas feeds 552, 554,556.

FIG. 7A is a schematic diagram of a distributed gas supply feed, 554,556, in accordance with embodiments of the present invention. One ormore of distributed gas supply feeds 554, 556 can include a plasmaarrestor 620.

FIGS. 7B-F are schematic diagrams of plasma arrestors 620, 620′, inaccordance with embodiments of the present invention. The plasmaarrestors 620, 620′ substantially prevents plasma from igniting insidethe distributed gas supply feed, 554, 556. Seals 702A, 702B prevent gasleakage.

The plasma arrestor 620 can include multiple small tubes 750 and flutedchannels 752 along the exterior portion of the plasma arrestor. Thesmall tubes 750 and the fluted channels 752 have a width small enoughthat it extinguishes any plasma that reaches the plasma arrestor 620.The plasma arrestor 620 can also include a grounding electrode (notshown) that can assist in extinguishing any plasma that reaches theplasma arrestor.

An alternative plasma arrestor 620′ has a spiral outer coil 760 thatforms a spiral channel having a width small enough that it extinguishesany plasma that reaches a plasma arrestor. The spiral outer coil 760 canalso be grounded to assist in extinguishing the plasma that reaches theplasma arrestor 620′. The plasma arrestors 620, 620′ can be made from aceramic material (e.g., alumina or similar).

FIG. 8 is a flowchart diagram that illustrates the method operations 800performed in selecting an edge etch rate using distributed gas zones502, 504, 506, in accordance with one embodiment of the presentinvention. The operations illustrated herein are by way of example, asit should be understood that some operations may have sub-operations andin other instances, certain operations described herein may not beincluded in the illustrated operations. With this in mind, the methodand operations 800 will now be described.

In operation 802 a plasma 260 is created in the plasma chamber 262. Inan operation 804 an inquiry is made to determine whether to reduce theetch rate over inner gas distribution zone 1, 502. If the inner gasdistribution zone 1, 502 etch rate is to be reduced then the methodoperations continue in an operation 806. If the inner gas distributionzone 1, 502 etch rate is not to be reduced then the method operationscontinue in an operation 808.

In operation 806 tuning gas is injected into the inner gas distributionzone 1, 502, and the method operations continue in an operation 816.

In operation 808, an inquiry is made to determine whether to reduce theetch rate over mid gas distribution zone 2, 504. If the mid gasdistribution zone 2, 504 etch rate is to be reduced then the methodoperations continue in an operation 810. If the mid gas distributionzone 2, 504 etch rate is not to be reduced then the method operationscontinue in an operation 812.

In operation 810 tuning gas is injected into the mid gas distributionzone 2, 504, and the method operations continue in an operation 816.

In operation 812, an inquiry is made to determine whether to reduce theetch rate over outer gas distribution zone 3, 506. If the outer gasdistribution zone 3, 506 etch rate is to be reduced then the methodoperations continue in an operation 814. If the outer gas distributionzone 3, 506 etch rate is not to be reduced then the method operationscontinue in an operation 816.

In operation 812 tuning gas is injected into the outer gas distributionzone 3, 506, and the method operations continue in an operation 816.

In operation 816, an inquiry is made to determine whether to the etchprocessing is complete. If the etch processing is complete then themethod operations can end. If the etch processing is not complete thenthe method operations continue in operation 804 as described above.

FIG. 9 is a simplified schematic diagram of a computer system 900 inaccordance with embodiments of the present invention. It should beappreciated that the methods described herein may be performed with adigital processing system, such as a conventional, general-purposecomputer system. Special purpose computers, which are designed orprogrammed to perform only one function, may be used in the alternative.The computer system includes a central processing unit (CPU) 904, whichis coupled through bus 910 to random access memory (RAM) 928, read-onlymemory (ROM) 912, and mass storage device 914. Phase control program 908resides in random access memory (RAM) 928, but can also reside in massstorage 914 or ROM 912.

Mass storage device 914 represents a persistent data storage device suchas a floppy disc drive or a fixed disc drive, which may be local orremote. Network interface 930 provides connections via network 932,allowing communications with other devices. It should be appreciatedthat CPU 904 may be embodied in a general-purpose processor, a specialpurpose processor, or a specially programmed logic device. Input/Output(I/O) interface provides communication with different peripherals and isconnected with CPU 904, RAM 928, ROM 912, and mass storage device 914,through bus 910. Sample peripherals include display 918, keyboard 922,cursor control 924, removable media device 934, etc.

Display 918 is configured to display the user interfaces describedherein. Keyboard 922, cursor control 924, removable media device 934,and other peripherals are coupled to I/O interface 920 in order tocommunicate information in command selections to CPU 904. It should beappreciated that data to and from external devices may be communicatedthrough I/O interface 920. The embodiments can also be practiced indistributed computing environments where tasks are performed by remoteprocessing devices that are linked through a wire-based or wirelessnetwork.

FIG. 10A is a schematic diagram of the heated edge ring 307, inaccordance with embodiments of the present invention. A heater 205 canoptionally be included to heat the edge ring 307.

FIGS. 10B and 10C are schematic diagrams of a cam lock 1010, inaccordance with embodiments of the present invention. The cam lock 1010includes a cam lock shaft 1011 and a cam lock head 1012. The cam lock1010 couples with a latch 1014 to secure the electrostatic chuck 140 tothe facilities plate 1015.

FIGS. 10D and 10E are schematic diagrams of electrical connections 1020,1022 to the heaters 205, in accordance with embodiments of the presentinvention. The electrical connections 1020, 1022 couple electrical powerto the heaters 205. The electrical connections 1020, 1022 are coupled tothe heaters 205 when the cam locks 1010 secure the electrostatic chuck140 to the facilities plate 1015.

FIG. 10F is a schematic diagram of an optical temperature sensor 1030,in accordance with embodiments of the present invention. The opticaltemperature sensor 1030 monitors the temperature of the edge ring 307and couples this temperature data to the system controller.

With the above embodiments in mind, it should be understood that theinvention may employ various computer-implemented operations involvingdata stored in computer systems. These operations are those requiringphysical manipulation of physical quantities. Usually, though notnecessarily, these quantities take the form of electrical or magneticsignals capable of being stored, transferred, combined, compared, andotherwise manipulated. Further, the manipulations performed are oftenreferred to in terms, such as producing, identifying, determining, orcomparing.

The invention can also be embodied as computer readable code and/orlogic on a computer readable medium. The computer readable medium is anydata storage device that can store data which can thereafter be read bya computer system. Examples of the computer readable medium include harddrives, network attached storage (NAS), logic circuits, read-onlymemory, random-access memory, CD-ROMs, CD-Rs, CD-RWs, magnetic tapes,and other optical and non-optical data storage devices. The computerreadable medium can also be distributed over a network coupled computersystems so that the computer readable code is stored and executed in adistributed fashion.

It will be further appreciated that the instructions represented by theoperations in the above figures are not required to be performed in theorder illustrated, and that all the processing represented by theoperations may not be necessary to practice the invention. Further, theprocesses described in any of the above figures can also be implementedin software stored in any one of or combinations of the RAM, the ROM, orthe hard disk drive.

Although the foregoing invention has been described in some detail forpurposes of clarity of understanding, it will be apparent that certainchanges and modifications may be practiced within the scope of theappended claims. Accordingly, the present embodiments are to beconsidered as illustrative and not restrictive, and the invention is notto be limited to the details given herein, but may be modified withinthe scope and equivalents of the appended claims.

What is claimed is:
 1. A plasma processing system comprising: a plasma chamber including: a substrate support; and an upper electrode opposite the substrate support, the upper electrode having a plurality of concentric temperature control zones; and a controller coupled to the plasma chamber.
 2. The plasma processing system of claim 1, wherein the substrate support includes an edge ring proximate to an outer perimeter of a supported substrate.
 3. Plasma processing system of claim 2, wherein the edge ring includes a temperature control mechanism capable of heating or cooling the edge ring to a selected edge ring temperature.
 4. The plasma processing system of claim 3, wherein at least one of the plurality of concentric temperature control zones extends outside a radius of the edge ring.
 5. The plasma processing system of claim 1, wherein each one of the plurality of concentric temperature control zones includes a temperature control mechanism.
 6. The plasma processing system of claim 5, wherein the temperature control mechanism is capable of heating or cooling a respective one of the plurality of concentric temperature control zones to a corresponding selected temperature control zone temperature.
 7. The plasma processing system of claim 1, wherein the substrate support is capable of heating or cooling a supported substrate to a selected substrate temperature.
 8. The plasma processing system of claim 1, wherein the plasma chamber further includes a plasma confinement structure, the plasma confinement structure extends outside a radius of the substrate support.
 9. The plasma processing system of claim 1, further comprising an RF source coupled to the inner upper electrode.
 10. The plasma processing system of claim 9, wherein the RF source coupled to the inner upper electrode is capable of heating the inner upper electrode.
 11. A plasma processing system comprising: a plasma chamber including: a substrate support includes an edge ring proximate to an outer perimeter of a supported substrate wherein the edge ring includes a temperature control mechanism capable of heating or cooling the edge ring to a selected edge ring temperature; and an upper electrode opposite the substrate support, the upper electrode having a plurality of concentric temperature control zones wherein at least one of the plurality of concentric temperature control zones extends outside a radius of the edge ring; a plasma confinement structure, the plasma confinement structure extends outside a radius of the substrate support; and a controller coupled to the plasma chamber.
 12. A method of selecting an edge etch rate using a dual temperature zone upper electrode comprising: creating a plasma in a plasma chamber; reducing an edge etch rate including increasing an inner upper electrode temperature to a temperature greater than an outer upper electrode temperature; and increasing an edge etch rate including decreasing an inner upper electrode temperature to a temperature less than an outer upper electrode temperature.
 13. The method of claim 12, wherein the outer upper electrode temperature is in a plasma confinement structure, the plasma confinement structure extends outside a radius of a substrate support in the plasma chamber.
 14. The method of claim 12, wherein the inner upper electrode temperature is opposite a substrate support in the plasma chamber.
 15. The method of claim 12, wherein reducing the edge etch rate further including increasing a substrate temperature to a temperature greater than an outer upper electrode temperature.
 16. The method of claim 12, wherein increasing an edge etch rate further including decreasing an inner upper electrode temperature to a temperature less than an edge ring temperature, the edge ring proximate to an outer perimeter of a substrate support in the plasma chamber.
 17. The method of claim 12, wherein increasing the inner upper electrode temperature includes applying an RF signal to the inner upper electrode.
 18. The method of claim 17, wherein applying the RF signal to the inner upper electrode includes cooling the inner upper electrode.
 19. The method of claim 17, wherein heating the inner upper electrode includes maintaining the inner upper electrode at a set point temperature including: applying the RF signal to the inner upper electrode during a first period and simultaneously cooling the inner upper electrode during the first period; and stopping applying the RF signal to the inner upper electrode during a second period and simultaneously heating the inner upper electrode during the second period.
 20. The method of claim 17, wherein heating the inner upper electrode includes maintaining the inner upper electrode at a set point temperature including: applying the RF signal to the inner upper electrode during a first period and simultaneously heating the outer upper electrode during the first period; and stopping applying the RF signal to the inner upper electrode during a second period and simultaneously cooling the outer upper electrode during the second period. 